I am working on bomberman second attack. I had limited success on 64 with unfixable glitches due to breakpoints not working on nemu64. Second attack will be IPS patch for a .z64 ROM. The patch will also fix the letterboxing. Might need to do breakpoints on mirrors for bomberman 64.

I typically find the generation of the scissoring display list command and change some of the values that go into the command for no letterbox. Might also change some instances of values going into the fill rect command as well to get rid of letterbox. If the game doesnt run in Nemu64 I typically cannot make a code. Also how would we apply IPS patches on the fly. It will require big-endian ROMs

Look up F3DEX opcodes for the display list commands. A requirement is the game being able to run in nemu64. If it runs with audio only or serious GFX glitches change your GFX plugin. Some parameters to the commands will be multiplied by 4.

That's because the process is highly game specific past that. You also need MIPS assembly knowledge. I typically start widescreen hacks from finding a specific display list command as well. The upper 32 bits of the command is DA380007. That command loads the projection matrix. The lower 32 bits is the physical address of it.